The present invention relates to a projector using a video display for projecting images on a screen, such as a liquid crystal projector, a reflection image projector, an optical unit such as a rear projection television display, and a projection type video display.
A known single-chip projection display passes a light beam emitted by a white light source sequentially through an integrator and a polarization beam splitter (herein-after, “PBS”), divides the light beam into an R color bar, a B color bar and a G color bar using a plurality of dichroic mirrors, deflects the color bars with a rotating polygon reflector to irradiate different parts of a light bulb simultaneously. At the same time, the color bars are moved in a fixed direction for scanning or scrolling on the light bulb. Techniques relating to this single-chip projection display are disclosed in JP-A 2004-170549 and U.S. Pat. Pub. No. 2003/095213, for example.
Such a scanning (or scrolling) projection display device scrolls information represented by the color bars of the three colors and displayed on a light bulb by a rotating polygon reflector. FIG. 1 shows a projection display device disclosed in U.S. Pat. Pub. No. 2003/095213 by way of example. As shown in FIG. 1, the projection display device forms three adjacent color bars using a color separator including dichroic prisms and, at the same time, scrolls the three color bars with a lens array wheel. A scanning projection display device disclosed in JP-A 2004-170549, as shown in FIGS. 1, 3A and 3B attached to the specification thereof, deflects separated three color beams individually with rotating polygon reflectors placed in the optical paths of the three color light beams for scrolling.